Propeller pump or blower



Jan. 14, 1958 F. c. GILMAN PROPELLER PUMP OR BLOWER Filed Aug. 18, 1955 FIG FIG FREDERICK C- Gl-Wv'fm United States Patent PROPELLER PUMP OR BLOWER Frederick C. Gilman, Pompton Lakes, N. J., assignor to Worthington Corporation, Harrison, N. J., a corporation of Delaware Application August 18, 1953, Serial No. 375,036

Claims. (Cl. 103-41) The present invention relates to propeller pumps or axial ow pumps and more particularly to a method and apparatus to provide controllable circulation for single stage propeller pumps whereby a broad range of high eiciency, a stable head characteristic and low starting power requirements may be provided in such pumps. The present invention relates to such pumps or machines whether employed for pumping liquids, gas, air or other fluids.

Fixed geometry axial ow pumps and blowers of conventional form are either unstable in their head vs. capacity characteristics or they suffer from increased internal fluid friction losses if the blades of thepropeller are set at a ilat angle to avoid the pressure instability.

The present invention contemplates the use of recirculation through the propeller of the pump to permit the use of highly eiiicient blading avoiding instability by maintaining suflicient ilow over the blades of the propeller even when less than the stable quantity of iluid is being delivered by the pump.

In some installations propeller pumps are required to start against a closed discharge valve. In such cases excessive starting power is required unless low speed starting is provided. Since the driving motor of such pumps is usually more costly than the pump, any abnormal starting power requirements greatly increase the cost of the installation. To overcome this undesirable feature and to provide a broad range of eilicient stable operation, adjustable blade propellers are sometimes used on large pumps. Another construction which secures the benelits of the adjustable propeller pump in considerable measure is the use of fixed propeller blades with adjustable inlet guide vanes. While such constructions are in meas ure satisfactory, they are complicated and expensive to manufacture and to repair.

The present invention contemplates a construction to provide the advantages above set out in a simpler, less expensive construction and it employs fixed blades on both the pump propeller and the casing together with an adjustable gate which controls the quantity circulation of the fluid to provide internal recirculation of the fluid through the pump.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a propeller pump or blower of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure l is a vertical section through an improved axial ow or propeller pump constructed in accordance with the present invention.

Figure 2 is a cross section through the pump taken on the line 22 of Figure l.

Figure 3 is a cross section taken on the line 3--3 of Figure 1.

iCe

Referring more particularly to the drawings,I 1 indicates generically the casing of the propeller or axial flow pump which has an annular inlet 2 at its lower end and an upwardly curving throat 3 leading from the annular inlet 2 to the propeller blades 4. The liquid or lluid pumped is discharged in a substantially axial tlow from the propeller blades 4 through the annular outlet passage 5 within the casing.

The propeller structure generically indicated by the numeral 6, is attached to the driving shaft 7 which may be operated by any suitable type of a prime mover (not shown). As shown in Figure l of the drawings the driving shaft 7 is connected by suitable bolting 8 to the shell 9 of the propeller structure 6. The shell 9 is substantially in the forni ol :t dished disc which llares outwardly and upwardly from its point of connection with the shaft 7 and it has a plurality of guide vanes 10 rigidly attached thereto and connected at their ends which are remote from the shell disc 9 to an annular ring 11 as clearly shown in Figure l of the drawings. The vanes 10 are rigidly or non-adjustably connected to the shell 9 and are of the approved streamline llow construction employed in guide vanes of this type.

A propeller ring l2 is attached to the ring 11 in any suitable manner and it has the propeller blades 4 attached thereto. The propeller blades 4 are of the usual construction of propeller blades for lixed geometry axial flow pumps and blowers, designed, however, to provide a high degree of eliiciency in the pumping action of the pump and avoid instability by maintaining suflicient flow over the blades even when less than a stable quantity of iiuid is being delivered by the pump. As noted by particular reference to Figure l of the drawings the ring 12 and the ring 11 are so constructed that they provide an axial space within the propeller structure which opens out through the guide vanes itl into the discharge passage 5 of the pump so that during operation of the pump a percentage of the fluid being pumped will tlow through the spaces between the guide vanes 10, through the propeller structure back to the inlet side of the blades 4 of the propeller as indicated by the recirculation ow direction arrows A while the remainder of the fluid will follow the normal flow paths of the Huid being pumped as indicated by the arrows B.

For the purpose of regulating the quantity of fluid recirculated through the pump, an adjustable recirculation control gate 2t) is provided. The gate 20 is circular in cross-section as clearly shown in Figure 2 of the drawings and has operating rods 21 connected thereto which may be connected to any suitable operating mechanism to provide movement of the gate 20 in a direction parallel with the axis of the driving shaft 7. When the cylindrical recirculation control gate 20 is in the position shown in Figure l of the drawings, maximum recirculation of iluid pumped through the impeller of the pump is provided. However, by moving the cylindrical recirculation control gate Ztl over the inlet edges of the guide vanes 10 towards the propeller blades 4 the degree or crosssectional area oi the recirculation inlet may be varied for varying the quantity of the Huid being pumped which is recirculated through the propeller.

lf it is so desired a deflector 22 which, as shown in Figure l of the drawings, is substantially triangular in cross-section, may be placed in the pump casing 1 inwardly of the normal inlet 2 and below the propeller strncture 6 for the purpose of guiding and deecting the incoming fluid being pumped and the recirculated fluid towards the propeller blades 4.

It will be understood that the invention is not to be limited to the specic construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

what isclairtnetris:v

1; Inh an axial owpropeller pump,- ay casinghaving.

carrying ri'ng rotatable therewithl and'4 spaced' toprovidev communieatibnbetweeri the interior of'the` ringl and thel ca'siiigf outlet passage and arranged to" guide partA ofthe discharge new o'f fluid pumpedk by s 'ati' propeller blades' back througli the open' carrying ring toI the inletfside of the propeller blades, land adjustable means movable to' regulate-tnerea 'of tneconmuni'catihg spaces' between said;110W#guiding;vanesI and the outlet passage for con# trolling the quantity of 'iti carrying'i-ing: j l Y 2L propeller ptitnp a's claii'ned1 in; claiin' 1 wherein thelast mentioned mean'sfconsistsofan adjustable cylindrical` resiren.lationA` now-control gate, movable with relation"- to s a'id' re'c'irctilati'onl flbwguidingvanes to control the quantity o'fi fluid recirculatedthrough* said open carry# ing ring:

3. In arr axi'alfovv propeller"pump,4 aasing having" inlety vand outlet passages, a propellerunitV in said casing, meansfor rotating sai'd" propeller unit;- said` propeller un'it' including a propeller blade-carrying ring', propeller blades carried by said ring, a plurality of flow-guiding vanesf rigidly connected'g to said ring' an'd ldcatedy at the discharge side of' 'said' propeller blades and*y establishing vane' iluid-tlow passages from the outlet passage into the ring; the opening in said? ring c'u'rnrluriicatingl with recir'ciulat'ed through said' said inlet passage, and an adjustable means in said easing movable. to.. vary. theow.. area.of saidfluidfow passages.`

4. An axial flow propeller, pump as claimed in claim 3 wherein said adjustable means includes a movable gate movable between said flow-guiding vanes and the outlet passage to vary the flow area of said vane fluid-flow passages and regulate the recirculation duid-flow through the pump.

5. In an axial' il'w'prop'eller pump, a casing having inlet and. outlet passagesa propeller unit in said casing` ReferencesV Cited intlie le of this patent UNITED STATES PATENTS 1,261'24'57`v- .Stott Apr. 2, 1918 2,277,868 Meyerhoefer- Mar. 3l, 1942 2,3 79;'133A Curtis' June 26, 1945 2,380,606 Moody July 3l, 1945y 2,418,801 Baumann Apr. 18, 1947 2,52'05697 Smith Aug. 29, 1950 FOREIGN PATENTS 900,439

France -..a Iune't20, 1945 

